The MEMS technology is an advanced technology with fast development speed in recent years. Compared with the electronic components manufactured by the traditional technology, the components manufactured by the MEMS technology have notable advantages in volume, power consumption, weight, and cost. Besides, the MEMS components can be of mass production through advanced semiconductor manufacturing process. Nowadays, the MEMS components are actually applied in pressure sensors, accelerometers, gyroscopes, and silicon microphones, and the like.
However, the MEMS components also need to be electrically connected and integrated together with the integrated circuits (CMOS/Bipolar) including driver, detecting, signal processing, and the like to jointly form an independent system for integrated function. At present, there are a variety of available integration solutions, mainly two integration solutions: single-chip integration and multi-chip integration. The case where the circuit and the MEMS components are fabricated on the same chip is called single-chip integration. Regarding the single-chip integration, there are two types of processes among which one is called pre-CMOS and the other is called POST-CMOS determined by the manufacture sequence of the mountable components. The Pre-CMOS is a process with the MEMS component fabricated before the integrated circuit in the same chip. However, this process may result in polluting the later integrated circuit and may further pollute the corresponding manufacture machine. As a result, any other integrated circuits manufactured by such manufacture machine with the process may also be disabled. In a POST-CMOS process, the MEMS component is fabricated after the integrated circuit. Usually, the MEMS component needs high temperature in manufacturing, which may easily damage the integrated circuit. Although, disadvantages arising from the Pre-CMOS process and the POST-CMOS process can be avoided certain methods, such avoidance will result in the complexity of the process and accordingly enhance the manufacture cost. Consequently, the application range of the single-chip integration process is limited, and many MEMS components are selected to avoid using the single-chip integration process.
The multi-chip integration is another process with the MEMS component and the integrated circuit enclosed in a single encapsulation. In this process, different chips are firstly selected for manufacturing the MEMS component and the integrated circuit respectively, and then the chips are adjacently arranged in the same chip substrate. The MEMS component and the integrated circuit are electrically connected by means of wire bonding. Finally, the chips are packed through a ceramic or metal package process. The disadvantages of the solution are as follows: Firstly, because the electrical connection between the MEMS component and the integrated circuit is implemented by using a long wire, many interference signals may be introduced, resulting that the overall integration function of the system may be reduced. Secondly, because the MEMS components are generally movable parts whose size is of a micrometer scale, and these parts are more vulnerable. Therefore, plastic package cannot be used while integration package, but ceramic or metal package is used. This increases the cost. Usually the package cost of the MEMS components is 10-100 times the cost of the MEMS components.
Therefore, it is a technical issue to be addressed for those skilled in the art as how to solve the disadvantages in the prior art to achieve a low-cost integration solution.